Fungicidal composition comprising in particular an oil of plant origin with high drying power

ABSTRACT

The subject of the present invention is a fungicidal composition useful for the treatment of fungal diseases of crops and which comprises in particular at least one vegetable oil with high siccative power, as well as a method of treating crops using such a composition.

The subject of the present invention is a fungicidal composition usefulfor the treatment of fungal diseases of crops and which comprises avegetable oil with high siccative power, and a method of treating cropsusing a composition according to the invention.

It is always desirable to reduce the doses of chemical products spreadin the environment, for treating fungal diseases of crops, in particularby reducing the doses for application.

To do this, certain adjuvants, termed biological activators such asmineral oils, wetting agents and penetrating agents are combined withcommercial proprietaries, and now make it possible, for example, tocombine a mineral oil-type adjuvant with fungicidal compounds, which hasthe advantage of reducing the applied dose of fungicidal compounds. Thisthus broadens the possibilities of choices offered to farmers, so thatthe latter finds the solution best suited to their particular problem.

On the other hand, the use of some of these proprietaries is restrictedwhen cases of phytotoxicity are observed on certain crops.

One aim of the invention is therefore to provide a novel fungicidalcomposition, allowing better selectivity even on so-called sensitivecrops, while preserving an equivalent biological activity, preventivelyor curatively, against various diseases.

It has now been found that these aims could be achieved using thefungicidal composition according to the invention.

The subject of the present invention is a fungicidal composition usefulfor the treatment of fungal diseases of crops, based on at least onefungicidal compound and at least one adjuvant of the oil of plant origintype possessing high siccative power, the latter acting as activator(doping agent). It also relates to a method of treating crops with thesame aim.

A fairly large number of examples of the use of vegetable oils informulations of pesticidal, and in particular fungicidal, compounds, areknown in the literature.

Nevertheless, no use of vegetable oils possessing high siccative powerin fungicidal compositions has ever been reported.

Thus, and most surprisingly, such a use in fungicidal compositionsaccording to the invention has made it possible to obtain particularlyadvantageous results.

The fungicidal compounds according to the present invention are, for themost part, known to farmers in particular for their efficacy against thediseases affecting or likely to affect cereals and other crops.

One advantage is also noted with regard to the use of certain vegetableoils which make it possible to reduce by 3 the dose of oil whilepreserving an equivalent biological efficacy.

Furthermore, the composition of the formulation proposed makes itpossible to obtain an excellent physical quality of the plant-protectionmixture for application and thus allows its use with various othercommercial combinations with no risk of physicochemical incompatibility.

Such a stability of the plant-protection mixture for application of thefungicidal composition according to the invention also makes it possibleto be able to formulate certain active substances which are otherwisedifficult or even impossible to formulate.

Another aim of the invention is to provide a novel fungicidalcombination useful in the preventive or curative treatment of diseases.

Another aim of the invention is to provide a fungicidal combinationallowing improved efficacy, preventively or curatively, against variousdiseases and/or improved selectivity.

Another aim of the invention is to improve, in terms of persistance, theaction of the fungicidal compounds.

Another aim is to provide combinations which allow better resistance toadverse weather conditions, in particular to rain.

Surprisingly, a fungicidal composition has now been found which providescomplete or partial solutions to the problems and disadvantages whichhave just been mentioned.

The fungicidal composition according to the invention is characterizedin that it comprises at least one fungicidal compound A and at least oneoil B, this oil being of plant origin and possessing a high siccativepower.

The advantages linked to the selective use of vegetable oils possessinga high siccative power are in particular their nontoxicity or at thevery least a lower toxicity, compared with oils of mineral origin, alower phytotoxicity, and greater biodegradability.

According to a very advantageous embodiment of the fungicidalcomposition according to the invention, the fungicidal compound A ischosen from dicarboximide derivatives.

Among these dicarboximide derivatives, those of the group comprisingcaptan, captafol, chlozolinate, iprodione, procymidone and vinchlozolinare most particularly preferred.

Preferably, the fungicidal compound A is iprodione.

The invention therefore relates to a fungicidal composition combining anoily organic phase B which is a selection of unsaturated vegetable oil,of isomerized oil, of vegetable oil ester, of vegetable polymer and/orof a mixture of these various organic phases.

The vegetable oils may be of various origins, but those derived fromlinseed, sunflower, soya bean, maize, cotton, safflower and rapeseedwill be preferred. These oils are available in various qualities, namelycrude, refined or isomerized.

Preferably, the oil is a polyunsaturated vegetable oil which naturallycontains a large number of unsaturations.

The expression polyunsaturated oil is understood to mean a triglyceridein which the majority of the linear fatty chains possess two or threedouble bonds per chain, noted C18:2 or C18:3, that is to say chainsconsisting of 18 carbon atoms with 2 or 3 unsaturations.

As examples of polyunsaturated oils, there may be mentionedtriglycerides which predominantly contain so-called linoleic (C18:3)fatty acid chains such as linseed oil. As a guide, the composition byweight of this oil, characterized as fatty acids, may be within thefollowing range: 50 to 60% of C18:3-10 to 17% of C18:2-15 to 25% ofC18:1-2 to 4% of C18:0-5 to 8% of C16:0.

As an example of polyunsaturated oils, there may also be mentionedtriglycerides predominantly containing fatty acid chains of the linoleictype (C18:2) such as sunflower, maize, soya bean, safflower, cotton orrapeseed oil. As a guide, the composition of these oils, characterizedas fatty acids, may be within the following range: 45 to 70% ofC18:2-0.1 to 10% of C18:3-10 to 40% of C18:1-0.1 to 10% of C18:0-1 to26% of C16:0.

In other words, the oil coming within the scope of the present inventionis said to be siccative. The siccativity is either natural (siccative orsemi-siccative oils) or is obtained by chemical treatment of an oilwhich is not or not very siccative (so-called semisiccative ornonsiccative oils), this oil is then said to be isomerized.

The isomerization reaction consists in conjugating the double bonds inthe fatty acid chain —CH═CH—CH2-CH═CH—, so as to obtain conjugateddienes as follows —CH═CH—CH═CH—CH2-, thus increasing their siccativity(reactivity to air).

There may be mentioned, as isomerized oil, isomerized sunflower oil witha percentage of conjugated dienes of between 16 and 18%, but alsoisomerized linseed oil containing 11 to 13% of conjugated dienes.

For the fungicidal composition according to the invention, the use ofvegetable oils whose iodine value linked to their siccative power isgreater than 70, preferably greater than 90, more preferably stillgreater than 130, most preferably greater than 150, is preferred.

The present invention also relates to a combination of compounds A andB, such a combination is then a combination of two compounds, and may beapplied simultaneously as a ready-to-use mixture or as a freshly mademixture.

The compound B/compound A weight ratio in the composition according tothe invention is generally between 0.15 and 1.6,preferably between 0.2and 1.35, more preferably still between 0.25 and 1, or alternativelybetween 0.3 and 0.7, and most advantageously 0.45.

This composition is useful for the treatment of fungal diseases ofvarious crops. It is thus effective for treating rust, leaf blotch, netblotch of barley; for treating eyespot, rust, septoria diseases, yellowleaf spot and fusaria of wheat. It is also effective for controllinggrey mould, alternaria leaf spot, sclerotinia disease, net blotch andfusaria of protein-rich plants and of oil-producing plants (inparticular pea, rapeseed and maize) and for the treatment of turfdiseases such as rust, fusaria, sclerotinia and scurf.

It is particularly useful for the treatment of grey mould of vine,vegetable crops, the peach tree, the almond tree, the apple tree, thepear tree, the rape plant, the pea, the haricot bean and citrus;alternaria diseases of vegetable crops, the peach tree, the almond tree,the apple tree, the pear tree, the rape plant, potato and citrus; brownrot of the peach tree, the almond tree, the cherry tree; sclerotiniadisease of vegetable crops, the rape plant and potato; and scurf ofvegetable crops and rice.

Compounds A, contained in the composition according to the invention aredescribed in at least one of the following manuals:

“The pesticide manual” edited by Clive TOMLIN and published by theBritish Crop Protection Council, 11th edition;

“l′ Index phytosanitaire 2000”, published by the Association deCoordination Technique Agricole, 36th edition.

Compound B, also contained in the composition according to theinvention, is preferably refined and/or isomerized sunflower oil.

For their practical use, compounds A and B of the composition accordingto the invention are rarely used alone.

In the fungicidal composition according to the invention, compounds Aand B most often represent from 0.5 to 95% by weight of the saidcomposition as described above.

This may include the concentrated composition, that is to say thecommercial product combining the two active substances (for the purposesof the present text, the expression active substance should beunderstood to mean both compound A, a fungicidal compound, and compoundB, an adjuvant). This may also include the dilute composition ready tobe sprayed on the crop to be treated. In the latter case, the dilutionwith water may be carried out either using a concentrated commericalcomposition containing the two active substances (this mixture is called“ready mix”) or by means of the fresh mixture (called “tank mix”) of twocommercial concentrated compositions each containing one substance.

The composition according to the invention is liquid, and in this casein the form of a solution, suspension, emulsion or emulsifiableconcentrate. Oil-aqueous liquid compositions are preferred both fortheir ease of use and the simplicity of their manufacture. Preferably,an aqueous concentrated suspension is available which uses vegetable oilin the form of an oil-in-water emulsion.

More generally, the composition according to the invention may includeany solid or liquid additives corresponding to the customary techniquesof formulating plant-protection products.

The composition according to the invention may comprise, in addition,any customary additives or adjuvants of plant-protection compositions,in particular carriers, surfactants, adhering agents, flow-enhancingagents and antigels. This composition may also contain any sort of otheringredients such as, for example, protective colloids, adhesives,thickeners, thixotropic agents, penetrating agents, stabilizers,sequestrants, pigments, colorants, polymers and antifoams.

The term “carrier” in the present text denotes a natural or synthetic,organic or inorganic material with which the active substances arecombined to facilitate their application to the plant. This carrier istherefore generally inert and should be agriculturally acceptable, inparticular on the treated plant. The carrier may be solid (clays,natural or synthetic silicates, silica, resins, waxes, solidfertilizers, and the like) or liquid (water, alcohols, ketones,petroleum fractions, aromatic or paraffin hydrocarbons, chlorinatedhydrocarbons, liquefied gases and the like).

The surfactant may be an emulsifying, dispersing or wetting agent of theionic or nonionic type. There may be mentioned, for example, salts ofpolyacrylic acids, salts of lignosulphonic acids, salts ofphenolsulphonic or naphthalenesulphonic acids, polycondensates ofethylene oxide with fatty alcohols or with fatty acids or with fattyamines, substituted phenols (in particular alkylphenols or aryiphenols),salts of esters of sulphosuccinic acids, derivatives of taurine (inparticular alkyl taurates), phosphoric esters of polyoxyethylatedalcohols or phenols. The presence of at least one surfactant isdesirable to promote the dispersion of the active substances in waterand their good application to plants.

The expression oil-aqueous suspension concentrate is understood to meanan aqueous suspension in which the solid active substances are in theform of crystals in suspension in water and the oily organic phase, herethe vegetable oil plus an emulsifier, in the form of an oil-in-wateremulsion.

The suspension concentrates, which can also be applied by spraying, areprepared so as to obtain a stable fluid product which does not. giverise to thickening or to the formation of a sediment after storage or tophase separation, and they usually contain from 10 to 75% of activesubstances, from 0.5 to 15% of surfactants, from 0.1 to 10% ofthixotropic agents, from 0 to 10% of appropriate additives, such aspigments, colorants, antifoams, corrosion inhibitors, sterilizers,penetrating agents, adhesives and, as carrier, water or an organicliquid in which the active substances are not or not very soluble.

Some organic solid substances or inorganic salts may be dissolved ordispersed in the carrier to prevent sedimentation or as antigel for thewater.

According to an advantageous variant of the invention and by way ofexample, here is a composition of the oil-aqueous suspension concentratetype:

EXAMPLE SC1

Active substance 375 Ethoxylated polyararylphenol 60 phosphate potassiumsalt Dioctyl sulphosuccinate sodium salt 10 Ethoxylated oleic acid 8.5Polyunsaturated vegetable oil 170 Monopropylene glycol 50 Polysaccharide1.4 1,2-Benzisothiazolin-3-one 0.7 Isotridecanol 10 Citric acidmonohydrate 1 Water (qs 1 litre)

The composition according to the invention is prepared according tomethods known per se. An example of a method, as a guide, is describedbelow:

-   -   Add simultaneously, to water with stirring, monopropylene        glycol, isotridecanol, ethoxylated polyararylphenol phosphate        potassium salt, dioctyl sulphosuccinate sodium salt, citric acid        monohydrate.    -   Continue stirring so as to disperse and dissolve the        constituents.    -   Then add, with stirring, the active substance.    -   The suspension is pre-ground with the aid of a colloid mill and        then ground to the final particle size with the aid of a ball        mill.    -   With stirring, add the solution containing 2% of polysaccharide        and 1% of 1,2-benzisothiazolin-3-one to the ground suspension.    -   With stirring, add the oily phase, consisting of the homogeneous        mixture of vegetable oil and ethoxylated oleic acid, so as to        form the oil-in-water emulsion.

The fungicidal composition which is the subject of the invention isapplied by means of various methods of treatment such as spraying ontothe aerial parts of the crops to be treated with a liquid comprising thesaid composition, sprinkling, injection into the trees and coating.

Spraying a liquid on the aerial parts of the crops to be treated is thepreferred method of treatment.

The invention finally relates to a method of treatment intended forcombating or preventing fungal diseases of crops, characterized in thatan effective and non-phytotoxic dose of a composition according to theinvention is applied to the aerial parts of the plants.

The expression “effective and non-phytotoxic quantity” is understood tomean a quantity of composition according to the invention sufficient toallow control or destruction of the fungi present or likely to appear onthe crops, and resulting in no symptom of phytotoxicity for the saidcrops. Such a quantity is likely to vary within broad limits dependingon the fungus to be combated, the type of crop, the climatic conditionsand the compounds included in the fungicidal composition according tothe invention. This quantity may be determined by systematic fieldtrials, within the capability of persons skilled in the art.

These combinations are advantageously used so that the applied dose isbetween 250 and 1 000 g/ha, preferably between 500 and 750 g/ha forcompound A and between 0.25 to 0.45 times the dose of compound A, thatis from 225 to 337.5 g/ha for a ratio of 0.45 P (P=guarantee in relationto active substance) for compound B (when A is taken at 1st preferencedoses of 500 to 750 g/ha).

These doses depend on the plant treated, the degree of infestation, theclimatic conditions and the like. For example, in the case of turf, thedose of A may be up to 5 kg/ha.

Phytopathogenic fungi of crops which may be combated by this process arein particular those:

-   -   of the adelomycetes group:        -   of the genus Alternaria, for example A. solani, A. citri, A.            mali, A. kikuchiana, A. alternate, A. porri, A.            brassicae, A. brassicicola, A. dauci, and the like        -   of the genus Botrytis, for example B. cinerea or B.            squamosa,        -   of the genus Sclerotinia, for example S. sclerotinium, S.            minor or S. homeocarpa,        -   of the genus Penicillium, for example P. digitatum, P.            expansum,        -   of the genus Monilia, for example M. Mali, M. laxa, M.            fructigena,        -   of the genus Rhizopus, for example R. stolonifer,        -   of the genus Sclerotium, for example S. cepivorum,        -   of the genus Fusariumr, for example F. roseum,        -   of the genus Helminthosporium, for example H. allii,        -   of the genus Ascochyta, for example A. pisi,        -   of the genus Microdochium, for example M. nivale,    -   of the Basidiomycetes group:        -   of the family Rhizoctonia spp.

A classification made, no longer based on the fungi targeted, but on thetarget crops may be illustrated as below:

-   -   barley: net blotch (Helminthosporium),    -   rapeseed: alternaria leaf spot (Alternaria spp.), grey mould        (Botrytis cinerea), sclerotinia diseases (Sclerotinia        sclerotiorum)    -   vine: grey mould (Botrytis cinerea),    -   Solanaceae: alternaria leaf spot (Alternaria solani) and grey        mould (Botrytis cinerea) in particular,    -   vegetable crops: alternaria leaf spot (Alternaria spp.),        sclerotinia diseases (Sclerotinia spp.), grey mould (Botrytis        cinerea), foot or root rot (Rhizoctonia spp.),    -   rice: foot or root rot (Rhizoctonia spp.), decoloration of the        grains (Alternaria spp., Helminthosporium spp., and the like),    -   arboriculture: alternaria leaf spot (Alternaria spp.), grey        mould (Botrytis cinerea) and brown rot (Monilia fructigena),    -   citrus: scab (Elsinoe fawcetti), green and blue moulds        (Penicillium digitatum and P. expansum),    -   turf: rust, oidium, net blotch, telluric diseases (Microdochium        nivale, Pythium spp. Rhizoctonia solani, Sclerotinia homeocarpa        and the like).

Among the crops suitable for the method of treatment according to theinvention, there may be mentioned cereals, in particular barley,protein-rich plants and oil-producing plants, such as peas, rapeseed,sunflower, maize, vine, potato, tomato, vegetable crops (lettuce,Cucurbitaceae and the like), rice, arboriculture (apple tree, pear tree,cherry tree and the like), citrus and turf.

In the method of treatment according to the invention, components A andB of the composition according to the invention are generally appliedsimultaneously, by means of a composition according to the inventionprepared from a ready-to-use concentrate or from a tank mix.

Another aspect of the invention relates to a product for applyingsimultaneously, sequentially or alternately compounds A and B of thefungicidal composition according to the invention.

The following examples are given without limitation of the advantageousproperties of the combinations according to the invention.

The compositions, numbered with roman numerals, are of the typedescribed above.

EXAMPLE 1

In this study, the effect of the nature of the vegetable or mineral oilis compared in terms of selectivity and efficacy, with or without rain,by means of two formulations, numbered in roman numerals, such as:

-   -   I: 255 g/l of iprodione+255 g/l of mineral oil SIB (that is to        say Summer Insecticide Base) (SC).    -   II: 255 g/l of iprodione+255 g/l of vegetable oil Rapeseed CT        (SC).

The experimental protocol relating to the study of the selectivity ontobacco plants is the following:

The two formulations are sprayed at doses of 750 and 1500 g ofiprodione/ha in a plant-protection mixture volume of 150 1/ha on 2-weekold young tobacco plants (4-6 leaf stage) (3 repetitions/test factor).After drying of the products sprayed onto leaves, the plants are placedin a controlled environment cabinet at 25° C. during the day and 20° C.during the night (photoperiod 16 h/8 h). A phytotoxicity score (as % ofsurface attacked) is determined after 7 days (7 JAT1) followed by asecond treatment and then the placing of the plants under the sameconditions as above. A final phytotoxicity score is determined after 7days (7 JAT2). Selectivity 7 JAT1 7 JAT2 I  750 g/ha 1 P SIB 0.7 1.01500 g/ha mineral 2.3 4.3 II  750 g/ha 1 P Rapeseed CT 1.0 1.0 1500 g/havegetable 1.3 1.3

The formulation based on rapeseed vegetable oil is found to be moreselective than the formulation based on mineral oil Summer InsecticideBase for the same dose of oil.

The efficacy is determined against Botrytis cinerea of gherkin in thepresence or in the absence of washing out, that is to say with orwithout rain. For this study, the experimental protocol is thefollowing:

The formulations under study are used at doses of 50-100-200 and 400 ppmof iprodione (test without washing out) or 100-200-400and 800 ppm ofiprodione (test with washing out). They are sprayed on gherkins, PetitVert de Paris variety, at the cotyledon-first visible leaf stage (2×3repeats/test factor). Four hours after the treatment, the groups of 3plants/dose of fungicide under study are subjected to washing out with25 mm of rain for 30 min. A day after the treatment, the gherkin plantsare contaminated by depositing drops of water containing an inoculum at150 000 spores of Botrytis cinerea/ml of inoculum. They are then placedin a controlled environment cabinet at 12-15° C., 100% RH. A score (in %of surface attacked) is determined 7 days after the inoculation. Thedata then serve to establish a sigmoid type dose-response curve whichmakes it possible to determine the IC90 (concentration causing 90%inhibition of the disease) as well as the confidence interval in whicheach IC90 exists. Efficacy and resistance to rain IC90 min. IC max. IC I1 P SIB without rain mineral 137 96 194 with rain 459 383 550 II 1 PRapeseed without rain CT 228 188 273 vegetable with rain 473 387 572

The formulation based on rapeseed vegetable oil has efficacy withoutrain which is slightly less than that based on mineral oil SIB, but witha nonsignificant difference in efficacy.

On the other hand, this formulation based on rapeseed oil exhibitsefficacy in the presence of washing out with rain which is equivalent tothe formulation containing the same dose of mineral oil SIB.

EXAMPLE 2

In this study, the effect of the nature of the vegetable or mineral oilis compared in terms of efficacy in the presence of rain (resistance torain), by means of two formulations such as:

-   -   III: 255 g/l of iprodione+350 g/l of mineral oil SIB (SC).    -   IV: 500 g/l of iprodione+125 g/l of linseed oil TS (SC).

The efficacy is determined against Botrytis cineria of gherkin in thepresence of rain. For this study, the experimental protocol is the sameas above. Resistance to rain IC90 min. IC max. IC III 1.35 P SIB 80 593109 with rain mineral 5 3 IV 0.25 P 96 915 101 with rain linseed TS 2 2

The linseed vegetable oil-based formulation appears slightly lesseffective than that based on mineral oil but this difference is notsignificant. This linseed vegetable oil-based formulation thereforeexhibits efficacy in the presence of rain (resistance to washing out)equivalent to the formulation containing 1.35 P of mineral oil. Itshould be noted that the dose of vegetable oil used is about 5 timesless than that used in III (for an equal dose of active substance).

EXAMPLE 3

In this study, the effect of the nature of the vegetable or mineral oilis compared in terms of efficacy in the presence of rain (resistance torain), by means of four formulations such as:

1. Fungicidal composition, characterized in that it comprises at leastone fungicidal compound A and at least one oil B, this oil being ofplant origin and possessing a high siccative power.
 2. Fungicidalcomposition according to the preceding claim, characterized in that thefungicidal compound A is chosen from dicarboximide derivatives. 3.Fungicidal composition according to either of the preceding claims,characterized in that the fungicidal compound A is chosen from captan,captafol, chlozolinate, iprodione, procymidone and vinclozolin. 4.Fungicidal composition according to of the preceding claims,characterized in that the vegetable oil B posseses an iodine value whichis greater than 70, preferably greater than 90, more preferably stillgreater than 130, and most preferably greater than
 150. 5. Fungicidalcomposition according to any of the preceding claims, characterized inthat the vegetable oil B is chosen from linseed, sunflower, soya bean,maize, cottonseed, safflower and rapeseed oils.
 6. Fungicidalcomposition according to of the preceding clalms, characterized in thatthe compound B/compound A weight ratio is between 0.15 and 1.6,preferably between 0.2 and 1.35, more preferably still between 0.25 and1, or alternatively between 0.3 and 0.7, and most advantageously 0.45.7. Fungicidal composition according to of the preceding claims,characterized in that compounds A and B represent from 0.5 to 95% byweight of the said composition.
 8. Method of treatment intended forcombating or preventing fungal diseases of crops, characterized in thatan effective and non-phytotoxic dose of a composition according to anyof the preceding is applied to the aerial parts of the plants.
 9. Methodaccording to the preceding claim, characterized in that the crops arechosen from cereals, in particular barley, protein-rich plants andoil-producing plants, such as peas, rapeseed, sunflower, maize, vine,potato, tomato, vegetable crops (lettuce, Cucurbitaceae and the like),rice, arboriculture (apple tree, pear tree, cherry tree and the like),citrus and turf.
 10. Method or treatment according to either of the twopreceding claims, during which a dose of between 250 and 1000 g/ha,preferably between 500 and 750 g/ha for compound A and between 0.25 and0.45 times the dose of compound A, that is from 225 to 337.5 g/ha for aratio of 0.45 P (P=guarantee in relation to active substance), forcompound B (when A is taken at 1st preference doses of 500 to 750 g/ha)is applied.
 11. Product for applying simultaneously, sequentially oralternately compounda A and B of the composition according to thepreceding claims.